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Reaction of E ‐2‐arylidene‐1‐indanones, Z‐aurones, Z‐1‐thioaurones and Z‐2‐arylidene‐2,3‐dihydro‐1 H ‐indol‐3‐ones with diazomethane
Author(s) -
Lévai Albert,
Patonay Tamás
Publication year - 1999
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570360328
Subject(s) - diazomethane , chemistry , cyclopropane , cycloaddition , medicinal chemistry , stereochemistry , ring (chemistry) , organic chemistry , catalysis
1,3‐Dipolar cycloaddition of E ‐2‐arylidene‐1‐indanones 1a‐h and Z‐aurones 3a‐c with diazomethane provided trans ‐spiro‐1‐pyrazolines 2a‐h and 4a‐c , respectively, as sole products. However, the same cycloaddition of Z‐1‐thioaurones 5a‐f afforded a mixture of Z‐α‐methyl‐1‐thioaurones 6a‐f and trans ‐cyclopropane derivatives 7a‐f as a result of the spontaneous denitrogenation of the initially formed 1‐pyrazolines. Similar reaction of Z‐2‐arylidene‐2,3‐dihydro‐1 H ‐indol‐3‐ones 8a,b and diazomethane yielded trans ‐cyclopropanes 9a,b . Structure and stereochemistry of the compounds synthesized have been elucidated by nmr spectroscopic measurements.